UN for Palestine Refugees Sweden and Canada have announced they will resume aid to UNRWA.
They were among 16 countries that suspended funding after Israel accused at least 12 UNRWA staff of involvement in the October 7 attack by Hamas.
The UN is investigating, and France's foreign minister is leading the review.
Sweden said on Saturday it would initially send 200 million kroner (£15m; $19m) to UNRWA after agreeing to additional checks on its costs and staff.
“The government has allocated 400 million kroner to UNRWA for 2024. Today's decision concerns the first payment of 200 million kroner,” it said in a statement.
It comes after Canada said on Friday it would resume funding for UNRWA while investigations into the agency's staff continue.
On October 7, Hamas gunmen crossed the border from Gaza into Israel, killing about 1,200 people and taking more than 250 hostages.
In response, Israel launched a campaign of airstrikes and ground occupation of the territory.
More than 30,900 people have been killed in Gaza, the territory's Hamas-run health ministry says, and the amount of aid reaching civilians has collapsed.
The UN has warned that a quarter of the Strip's population is on the brink of famine and children are dying of starvation.
UNRWA is the largest UN agency operating in Gaza. It provides health, education and other humanitarian assistance and employs about 13,000 people.
Its president, Philippe Lazzarini, said he was “cautiously optimistic” that donors would fund again within weeks.
He said the agency was “in mortal danger” after major donor countries cut off funding following allegations in late January that several employees were involved in the October 7 attack. Within days, Mr Lazzarini said an investigation was underway and that the staff had been dismissed “to protect the agency's ability to deliver humanitarian aid”.
“What is at stake today is the fate of the Palestinians in Gaza, who are facing an absolutely unprecedented humanitarian crisis,” Mr Lazzarini said.
The European Commission announced earlier this month that it would release 50 million euros in UNRWA funding.
Sweden is the fourth-largest contributor to the agency's budget, and Canada is the 11th-largest, 2022 data show.
Canada's decision was announced by the country's International Development Minister Ahmed Hussen in a statement on Friday.
He said it was created to “recognize the robust investigative process that is underway” and that “more can be done to respond to the urgent needs of Palestinian citizens”.
The Canadian Armed Forces will donate about 300 cargo parachutes to Jordan so they can be used to airlift supplies into Gaza.
Meanwhile, an internal draft document compiled by UNRWA and seen by the BBC alleges widespread abuse of Palestinians, including UNRWA staff, released from Israeli custody into Gaza.
In the document, former prisoners describe a range of ill-treatment.
It says: “Agency staff have been subjected to threats and coercion by Israeli authorities while in custody and pressured to publish false statements against the agency, including that the agency has links with Hamas and that UNRWA staff participated in the 7. October 2023 atrocities.”
In a statement to the BBC, the Israeli Defense Forces (IDF) denied the specific allegations and said: “Mistreatment of prisoners while in detention or during interrogation violates IDF values and violates the IDF and is therefore absolutely prohibited.”
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